The present invention relates to method and related apparatus for controlling switching between dedicated radio resources of a mobile radio communications network.
One option for supplying data/services by way of a mobile radio communications network is to offer such data/services by way of dedicated radio resources such as respective Radio Bearers (RBs).
To enhance the choice and variety of data/services available to one or more intended recipients, a requirement arises for the switching between different dedicated radio resources. However, current mechanisms for providing for such improved choice by allowing for switching between such dedicated radio resources exhibit disadvantageous limitations and inefficiencies.
As one of a variety of examples, reference is made in the following discussion to the provision of television services by way of a 3G mobile radio communications network as part of a Multimedia Broadcast Multicast Service (MBMS) broadcast.
In the operating environment for such television service, hereinafter referred to as “Mobile TV”, the recipient of the service can only watch one channel at a time. Then when a requirement for switching from one channel to another arises, a mechanism is required to allow for the switching between dedicated radio resources upon which the respective channels are transmitted.
While a possibility exists for providing Mobile TV by way of a point-to-multipoint broadcast system over a mobile radio communications network, radio inefficiencies exists as compared with the use of a point-to-point bearer as has been identified as part of the 3GPP RAN2 meeting of 28 Aug. 2006. Although the use of point-to-multipoint broadcast can offer advantageous characteristics with regard to cell load, the improved bearer and radio resource efficiencies offered by point-to-multipoint system, and the relatively likely low numbers of users requiring reception of a point-to-point MBMS broadcast within a specific cell, dictate that the efficiency requirements for Mobile TV can, in practice, be readily met without limitation by use of dedicated radio resources such as those provided by way of a point-to-point system.
When a recipient of the Mobile TV service wishes to switch from one channel to another, where both channels are transmitted by way of dedicated RB resources, the current RB has to be released prior to establishment of the new RB since two quite separate Radio Resource Control (RRC) messages for these purposes are derived from the 3G Radio Access Network (RAN).
Thus, with reference to, for example, Universal Telecommunications Radio Access Network (UTRAN) the current operational sequence for switching between channels comprises first the delivery of a request to the User Equipment (UE) for the release of the current RB, by means of an RB Release Message, followed by a request to the UE to set-up the RB relating to the new required channel by means of a RB Set-Up Message requiring the UE to perform Dedicated Physical Channel (DPCH) synchronization. Such synchronization is required twice and requires two responses, i.e. one response for each received message, to the UTRAN including Signaling Radio Bearer (SRB) delay time for each response sent.
The duplication of the DPCH frame synchronization, and the sending of the confirmation message for a new configuration, and the related SRB delay, disadvantageously limits the efficiency currently available for Mobile TV when employing the current point-to-point arrangement for switching between the dedicated RB channels.
While the use of point-to-point bearers as compared with a point-to-multipoint broadcast offers improved efficiency for Mobile TV, such efficiencies are nevertheless limited as discussed above.